In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter...In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter the micromixer by fluid flows and are actuated by an alternating magnetic field normal to the main flow. An important feature of micromixer which is not considered before by researchers is the particle entrance arrangement into the micromixer. This parameter could effectively affect the micromixer efficiency. There are two general micro magnetic particle entrance arrangements in magnetic bead micromixers: determined position entrance and random position entrance. In the case of determined position entrances, micro magnetic particles enter the micromixer at specific positions of entrance cross section. However, in a random position entrance,particles enter the microchannel with no order. In this study mixing efficiencies of identical magnetic bead micromixers which only differ in particle entrance arrangement are numerically investigated and compared.The results reported in this paper illustrate that the prepared computer code can be one of the most powerful and beneficial tools for the magnetic bead micromixer performance analysis. In addition, the results show that some features of the magnetic bead micromixer are strongly affected by the entrance arrangement of the particles.展开更多
Objective To evaluate the application of weak cation exchange (WCX) magnetic bead-based Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in detecting differentially expressed...Objective To evaluate the application of weak cation exchange (WCX) magnetic bead-based Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in detecting differentially expressed proteins in the urine of renal clear cell carcinoma (RCCC) and its value in the early diagnosis of RCCC.Methods Eleven newly diagnosed patients (10 males and 1 female, aged 46-78, mean 63 years) of renal clear cell carcinoma by biopsy and 10 healthy volunteers (all males, aged 25-32, mean 29.7 years) were enrolled in this study. Urine samples of the RCCC patients and healthy controls were collected in the morning.Weak cation exchange (WCX) bead-based MALDI-TOF MS technique was applied in detecting differential protein peaks in the urine of RCCC. ClinProTools2.2 software was utilized to determine the characteristic proteins in the urine of RCCC patients for the predictive model of RCCC.Results The technique identified 160 protein peaks in the urine that were different between RCCC patients and health controls; and among them, there was one peak (molecular weight of 2221.71 Da) with statistical significance (P=0.0304). With genetic algorithms and the support vector machine, we screened out 13 characteristic protein peaks for the predictive model.Conclusions The application of WCX magnetic bead-based MALDI-TOF MS in detecting differentiallyexpressed proteins in urine may have potential value for the early diagnosis of RCCC.展开更多
Tetrahydrofuran（THF） hydrate was formed in bulk as well as in glass beads pack with a mean diameter of 3.0 mm by controlling the temperature under ambient pressure.Images of THF hydrate formation procedure were obta...Tetrahydrofuran（THF） hydrate was formed in bulk as well as in glass beads pack with a mean diameter of 3.0 mm by controlling the temperature under ambient pressure.Images of THF hydrate formation procedure were obtained using the magnetic resonance imaging（MRI） technique.The experiment results showed that MRI is an effective method for the detection of hydrate formation.Saturation of hydrate formed both in bulk and glass beads can be confirmed by intensity integration of MRI images.展开更多
构建一种基于杂交链式反应(hybridization chain reaction,HCR)扩增的适配体磁珠荧光传感器。巧妙设计序列HP和发卡序列H1、H2,其中HP是由适配体序列与触发序列结合而成的,并且序列互补形成稳定的二级结构。然后采用戊二醇反应和亲和素...构建一种基于杂交链式反应(hybridization chain reaction,HCR)扩增的适配体磁珠荧光传感器。巧妙设计序列HP和发卡序列H1、H2,其中HP是由适配体序列与触发序列结合而成的,并且序列互补形成稳定的二级结构。然后采用戊二醇反应和亲和素-生物素反应进行适配体功能化磁珠的制备。将阪崎肠杆菌与适配体磁珠一起孵育,HP中的适配体序列识别靶标,引起HP构象变化,露出触发序列,通过HCR触发H1和H2的链状组装,产生长双链DNA。荧光指示剂SYBR Green I以插层和小槽结合的方式与HCR产物的长双链结合。最后加入氧化石墨烯(graphene oxide,GO)后,游离的H1、H2和SYBR Green I将通过π-π堆积紧密吸附在GO表面,荧光信号被猝灭。HCR产物不能被吸附在GO表面,因此与HCR产物结合的SYBR Green I发出依赖于靶浓度的强荧光信号,从而实现阪崎肠杆菌的定量检测。本方法在纯培养条件下的检出限为2CFU/mL,对奶粉的检出限为8CFU/g,对奶粉样品的检测结果与传统微生物培养法具有良好的一致性。该方法具有无需DNA提取,快速、稳定性高、高特异性和高灵敏度等优点,因此为阪崎肠杆菌的现场快速检测提供了一种很有潜力的方法。展开更多
利用磁珠法对甘蓝、白菜、芥菜、洋葱、黄瓜、番茄、辣椒等7种形状、大小不同的蔬菜单粒种子和幼苗进行DNA提取,采用内参基因Actin进行实时荧光定量PCR评价DNA质量,利用KASP(kompetitive allele specific PCR)标记检验DNA质量是否达到K...利用磁珠法对甘蓝、白菜、芥菜、洋葱、黄瓜、番茄、辣椒等7种形状、大小不同的蔬菜单粒种子和幼苗进行DNA提取,采用内参基因Actin进行实时荧光定量PCR评价DNA质量,利用KASP(kompetitive allele specific PCR)标记检验DNA质量是否达到KASP检测要求。结果显示,单粒种子磁珠法提取的各蔬菜DNA平均Ct值均处于19~24范围内。KASP检测进一步证实种子提取DNA的质量达到KASP标记分型的要求。综上所述,本研究建立了一种简单、经济、实用性强的单粒种子DNA提取方法,该方法对不同大小的蔬菜种子具有较好的稳定性,且大幅缩短了获得基因型数据的时间。展开更多
A high sensitive chemiluminescent magnetic enzyme-linked immunoassay method was established for Escherichia coli O157∶H7 determination.The bacterium antibody was labeled by alkaline phosphatase（ALP） that catalyzed ...A high sensitive chemiluminescent magnetic enzyme-linked immunoassay method was established for Escherichia coli O157∶H7 determination.The bacterium antibody was labeled by alkaline phosphatase（ALP） that catalyzed the decomposing of substrate 3-（2-spiroadamantane）-4-methoxy-4（3-phosphoryloxy）phenyl-1,2-dioxetane（AMPPD） to give the light emission.The sensitivity of the method is 8.5×104 Cell/mL with a linear range of 1.0×105—5.0×107 Cell/mL.The intra- and inter-assay CVs are 14.8% and 20.0% in pork samples, respectively.The correlation coefficient of present and the standard plate counting method is 0.981.The experiments with the spiked samples show that this method has great potential to be applied to（detecting） the concentration of Escherichia coli O157∶H7 in a variety of samples.展开更多
文摘In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter the micromixer by fluid flows and are actuated by an alternating magnetic field normal to the main flow. An important feature of micromixer which is not considered before by researchers is the particle entrance arrangement into the micromixer. This parameter could effectively affect the micromixer efficiency. There are two general micro magnetic particle entrance arrangements in magnetic bead micromixers: determined position entrance and random position entrance. In the case of determined position entrances, micro magnetic particles enter the micromixer at specific positions of entrance cross section. However, in a random position entrance,particles enter the microchannel with no order. In this study mixing efficiencies of identical magnetic bead micromixers which only differ in particle entrance arrangement are numerically investigated and compared.The results reported in this paper illustrate that the prepared computer code can be one of the most powerful and beneficial tools for the magnetic bead micromixer performance analysis. In addition, the results show that some features of the magnetic bead micromixer are strongly affected by the entrance arrangement of the particles.
文摘Objective To evaluate the application of weak cation exchange (WCX) magnetic bead-based Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in detecting differentially expressed proteins in the urine of renal clear cell carcinoma (RCCC) and its value in the early diagnosis of RCCC.Methods Eleven newly diagnosed patients (10 males and 1 female, aged 46-78, mean 63 years) of renal clear cell carcinoma by biopsy and 10 healthy volunteers (all males, aged 25-32, mean 29.7 years) were enrolled in this study. Urine samples of the RCCC patients and healthy controls were collected in the morning.Weak cation exchange (WCX) bead-based MALDI-TOF MS technique was applied in detecting differential protein peaks in the urine of RCCC. ClinProTools2.2 software was utilized to determine the characteristic proteins in the urine of RCCC patients for the predictive model of RCCC.Results The technique identified 160 protein peaks in the urine that were different between RCCC patients and health controls; and among them, there was one peak (molecular weight of 2221.71 Da) with statistical significance (P=0.0304). With genetic algorithms and the support vector machine, we screened out 13 characteristic protein peaks for the predictive model.Conclusions The application of WCX magnetic bead-based MALDI-TOF MS in detecting differentiallyexpressed proteins in urine may have potential value for the early diagnosis of RCCC.
基金supported by the National Science Foundation of China (NO.50736001)the National High Technology Research and Development Program("863" Program) of China (NO. 2006AA09209-5) the Major State Basic Research Development Program (973 Program) of China (NO. 2009CB219507)
文摘Tetrahydrofuran（THF） hydrate was formed in bulk as well as in glass beads pack with a mean diameter of 3.0 mm by controlling the temperature under ambient pressure.Images of THF hydrate formation procedure were obtained using the magnetic resonance imaging（MRI） technique.The experiment results showed that MRI is an effective method for the detection of hydrate formation.Saturation of hydrate formed both in bulk and glass beads can be confirmed by intensity integration of MRI images.
文摘构建一种基于杂交链式反应(hybridization chain reaction,HCR)扩增的适配体磁珠荧光传感器。巧妙设计序列HP和发卡序列H1、H2,其中HP是由适配体序列与触发序列结合而成的,并且序列互补形成稳定的二级结构。然后采用戊二醇反应和亲和素-生物素反应进行适配体功能化磁珠的制备。将阪崎肠杆菌与适配体磁珠一起孵育,HP中的适配体序列识别靶标,引起HP构象变化,露出触发序列,通过HCR触发H1和H2的链状组装,产生长双链DNA。荧光指示剂SYBR Green I以插层和小槽结合的方式与HCR产物的长双链结合。最后加入氧化石墨烯(graphene oxide,GO)后,游离的H1、H2和SYBR Green I将通过π-π堆积紧密吸附在GO表面,荧光信号被猝灭。HCR产物不能被吸附在GO表面,因此与HCR产物结合的SYBR Green I发出依赖于靶浓度的强荧光信号,从而实现阪崎肠杆菌的定量检测。本方法在纯培养条件下的检出限为2CFU/mL,对奶粉的检出限为8CFU/g,对奶粉样品的检测结果与传统微生物培养法具有良好的一致性。该方法具有无需DNA提取,快速、稳定性高、高特异性和高灵敏度等优点,因此为阪崎肠杆菌的现场快速检测提供了一种很有潜力的方法。
文摘利用磁珠法对甘蓝、白菜、芥菜、洋葱、黄瓜、番茄、辣椒等7种形状、大小不同的蔬菜单粒种子和幼苗进行DNA提取,采用内参基因Actin进行实时荧光定量PCR评价DNA质量,利用KASP(kompetitive allele specific PCR)标记检验DNA质量是否达到KASP检测要求。结果显示,单粒种子磁珠法提取的各蔬菜DNA平均Ct值均处于19~24范围内。KASP检测进一步证实种子提取DNA的质量达到KASP标记分型的要求。综上所述,本研究建立了一种简单、经济、实用性强的单粒种子DNA提取方法,该方法对不同大小的蔬菜种子具有较好的稳定性,且大幅缩短了获得基因型数据的时间。
文摘A high sensitive chemiluminescent magnetic enzyme-linked immunoassay method was established for Escherichia coli O157∶H7 determination.The bacterium antibody was labeled by alkaline phosphatase（ALP） that catalyzed the decomposing of substrate 3-（2-spiroadamantane）-4-methoxy-4（3-phosphoryloxy）phenyl-1,2-dioxetane（AMPPD） to give the light emission.The sensitivity of the method is 8.5×104 Cell/mL with a linear range of 1.0×105—5.0×107 Cell/mL.The intra- and inter-assay CVs are 14.8% and 20.0% in pork samples, respectively.The correlation coefficient of present and the standard plate counting method is 0.981.The experiments with the spiked samples show that this method has great potential to be applied to（detecting） the concentration of Escherichia coli O157∶H7 in a variety of samples.
